Knife



FIG. 1 is a top plan view of the design of the present invention for a knife;

FIG. 2 is a left side elevational view of FIG. 1, of which the right side is a mirror image thereof;

FIG. 3 is a front elevational view of the knife of FIG. 1, of which the rear view is a mirror image thereof; and,

FIG. 4 is a bottom plan view of the knife of FIG. 1. 

The ornamental design for a knife, as shown and described. 